Push Rods

Engines employ push rods to "open" and "close" the intake and exhaust valves, respectively. They are controlled by the lobes (bulges) on the camshaft, and they open and close in accordance with the engine's proper firing order. They can be opened to release burnt gases after detonation or to allow gas and oxygen to combine. Pushrods are not present in all types of engines, including rotor engines, 4-stroke engines, 2-stroke engines, and others.